The human metapneumovirus (hMPV) had been present in the human population for at least 50 years before it was first identified. Nature Medicine 7:P719-724 (2001). hMPV belongs to the Paramyxoviridae family of viruses, which includes several well known human pathogens such as measles virus, mumps virus, parainfluenza viruses and the human respiratory syncytial virus (hRSV). Based on hMPV's genetic sequence and structure, hMPV falls in the Pneumovirinae sub-family, together with its closest known human-infecting relative, Respiratory Syncytial Virus (RSV). However, hMPV's genetic sequence and structure differs sufficiently from that of RSV and is consequently placed in a separate genus—the Metapneumoviruses.
hMPV infects people of all ages and causes mild to severe respiratory infections. By the age of 5, most children have been infected with hMPV at least once. Severe disease requiring hospitalization occurs primarily in young children, the elderly and the immunocompromised. hMPV's clinical impact and epidemiology is very similar to that of RSV and infection by these two viruses cannot be distinguished on the bases of clinical signs alone.
Human metapneumovirus is common worldwide and seems to be most active in late winter and early spring—a period when many other respiratory viruses are also circulating. Several epidemiological surveys on hMPV infection have documented cases of metapneumovirus in Europe, Africa, Asia/Australia, Southern America, and Northern America. Worldwide, hMPV accounts for a significant portion of respiratory tract illnesses in hospitalized children, with high incidences occurring during the winter months in moderate climate zones and late spring-early summer in the subtropics. hMPV accounts for roughly 5 to 15% of the respiratory tract illnesses in hospitalized young children, with children <2 years of age being most at risk for serious hMPV infections. hMPV infections, like RSV and influenza virus infections, also account for respiratory tract infections in the elderly population and in patients with underlying disease.
What is needed is a simple, fast, and economical method to detect and identify types and subtypes of human metapneumovirus without the implementation of cell culture protocols, and without cross-reactivity to avian metapneumoviruses.